Evidence has been mounting over the years linking many diseases such as high blood pressure and lung cancer to cigarette smoking. The U.S. Surgeon General's report of 1988 on the health consequences of smoking estimated that in the United States alone about 300,000 deaths are caused each year by cigarette-related diseases. Indeed, excessive smoking is now recognized as one of the major health problems throughout the world.
Because of the addictive nature of nicotine, it is extremely difficult for a heavy smoker to stop smoking completely. Even though nicotine is one of the risk factors in tobacco smoke, other substances formed during the combustion of tobacco such as carbon monoxide, tar products, aldehydes and hydrocyanic acid are considered to be even greater risk factors.
Because of the addictive nature of nicotine, an acceptable alternative to smoking has been to provide nicotine in a form or manner other than by smoking. Several products have been developed that accomplish this result. The most successful product which is used as a smoking substitute and/or a smoking cessation aid is a chewing gum known as Nicorette.RTM. which contains nicotine as one of its active ingredients. This product is the only form of nicotine replacement which has been approved by the Food and Drug Administration to date.
In this chewing gum, nicotine is present in the form of a complex with an insoluble cation-exchanger (polacrilex) which is disbursed in a gum base. A buffering agent is included in this composition. U.S. Pat. Nos. 3,877,486; 3,901,248; and 3,845,217 are directed to this product.
Another product generally developed in this field is a smokeless cigarette sold under the trademark Favor which was on the United States market for about 18 months. This product was subsequently withdrawn because it did not satisfy the Food and Drug Administration requirements. Various embodiments of this product are described in U.S. Pat. Nos. 4,284,089; 4,800,903; and 4,813,437.
This product generally allows nicotine to be inhaled through an elongated tube in which a porous polymer reservoir containing nicotine free base is mounted. An air stream caused by suction from the user carries nicotine vapors into the lungs of the user to satisfy a nicotine craving.
In commercial embodiments of this product, the tube was formed of polybutyleneterephtalate (PBTP) and polyethylene (PE) polymers. This tube was wrapped in a polyehtyleneterephthalate (PET) wrapper in order to seal the nicotine from the atmosphere. However, it was unexpectedly found that the nicotine free base migrated through the packaging material and rapidly disappeared from the system because the material was more permeable than anticipated. It has been estimated that the shelf-life of the unrefrigerated vapor inhaler was approximately one month.
The present invention concerns an improvement of the container for holding the nicotine free base, thereby improving the shelf-life and purity of the nicotine stored.